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arXiv · 1501.00332

Mott-Kondo Insulator Behavior in the Iron Oxychalcogenides

B. Freelon·Yu Hao Liu·Jeng-Lung Chen·L. Craco·M. S. Laad·S. Leoni·Jiaqi Chen·Li Tao·Hangdong Wang·R. Flauca·Z. Yamani·Minghu Fang·Chinglin Chang·J. -H. Guo·Z. Hussain
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Abstract

We perform a combined experimental-theoretical study of the Fe-oxychalcogenides (FeO$\emph{Ch}$) series La$_{2}$O$_{2}$Fe$_{2}$O\emph{M}$_{2}$ (\emph{M}=S, Se), which is the latest among the Fe-based materials with the potential \ to show unconventional high-T$_{c}$ superconductivity (HTSC). A combination of incoherent Hubbard features in X-ray absorption (XAS) and resonant inelastic X-ray scattering (RIXS) spectra, as well as resitivity data, reveal that the parent FeO$\emph{Ch}$ are correlation-driven insulators. To uncover microscopics underlying these findings, we perform local density approximation-plus-dynamical mean field theory (LDA+DMFT) calculations that unravel a Mott-Kondo insulating state. Based upon good agreement between theory and a range of data, we propose that FeO$\emph{Ch}$ may constitute a new, ideal testing ground to explore HTSC arising from a strange metal proximate to a novel selective-Mott quantum criticality.

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B. Freelon, Yu Hao Liu, Jeng-Lung Chen, L. Craco, M. S. Laad, S. Leoni, Jiaqi Chen, Li Tao, Hangdong Wang, R. Flauca, Z. Yamani, Minghu Fang, Chinglin Chang, J. -H. Guo, Z. Hussain. 2015-01-02. Mott-Kondo Insulator Behavior in the Iron Oxychalcogenides. https://doi.org/10.1103/physrevb.92.155139

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